NESC0460 LIFE-1.

1. NAME OR DESIGNATION OF PROGRAM:  LIFE-1.

3. NATURE OF PHYSICAL PROBLEM SOLVED

LIFE1 is designed to predict the in-pile behaviour of cylindrical fast reactor fuel elements.
Assuming axial symmetry, the generalized plane-strain analysis combines models for fuel restructuring, migration of fuel consti- tuents, fuel swelling due to accumulation of fission products, fission gas release, hot pressing of the fuel, and clad swelling due to void nucleation and growth. An iterative procedure allows the code to compute the detailed thermal and mechanical response of the fuel element during any specified history of normal reactor power cycling. Up to 10 axial sections are allowed to account for variations in power and coolant temperature, and an option is included for treatment of encapsulated elements.

4. METHODS: METHOD OF SOLUTION

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

Up to ten axial sections are allowed to account for axial variations in the power and coolant temperature. In the heat transfer calculations, the fuel and clad may be divided up into arbitrary (user-specified) numbers of equal mass radial sections. In the stress-strain- swelling calculations the fuel is divided into three concentric regions and the clad is a single region. The materials proper- ties, temperatures, stresses, and deformations are averaged over each of these structural regions for the stress calculations.

6. TYPICAL RUNNING TIME

For steady-state runs using two axial sec- tions, one for the fuel section and one for the plenum, LIFE1 requires 5 to 6 minutes. For runs with varying power and coolant temperature history, the time required depends on the complexity of the specified operational history. The detailed analysis of an element run with actual EBR-II operating conditions for 2 1/2 years required 1 1/2 hours computing time. For more than two axial sections, the running time is correspondingly increased.

7. UNUSUAL FEATURES OF THE PROGRAM

LIFE1 allows study of the behaviour of fast reactor fuel elements under varying reactor operating conditions.

8. RELATED OR AUXILIARY PROGRAMS: RELATED AND AUXILIARY PROGRAMS

10. REFERENCES

- V.Z. Jankus and R.W. Weeks:
  LIFE-1, a FORTRAN-IV Computer Code for the Prediction of Fast-Reactor Fuel-Element Behavior.
  ANL-7736, November 1970.

11. MACHINE REQUIREMENTS

To compile the complete program on the ANL IBM360 system requires 472k storage, and to run the program requires 170k main storage.

13. OPERATING SYSTEM OR MONITOR UNDER WHICH PROGRAM IS EXECUTED:  OS/360.

14. ANY OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

A plotting routine for a Calcomp plotter is part of the program, but this is not written up in ANL-7736, and in the LIFE1 version being distributed no points are dumped for plotting. The subrou- tine TLEFT is part of the ANL 360 system environment. It returns to a calling program the difference, in hundredths of a second, between the time estimate on the job card and the total elapsed cpu + voluntary wait time. The function is called with one dummy argument. The value returned is in single precision, floating point, binary.  The value of the dummy argument remains unchanged.
Example x=TLEFT(y) causes x to be set equal to the time left, as described.

15. NAME AND ESTABLISHMENT OF AUTHOR

                 V. Z. Jankus and R. W. Weeks
                 Materials Science Division
                 Argonne National Laboratory
                 9700 South Cass Avenue
                 Argonne, Illinois  60439

File name	File description	Records
NESC0460_01.001	SOURCE PROGRAMME	2967
NESC0460_01.002	SAMPLE INPUT	63
NESC0460_01.003	SAMPLE OUTPUT	1453